Information About CTI CSTA Protocol Suite

CTI CSTA in Cisco Unified CME

The CTI CSTA Protocol Suite in Cisco Unified CME 8.0 and later versions provides third-party call-control capabilities for computer-based CSTA client applications, such as a Microsoft Office Communicator (MOC) client through Microsoft Office Communications Server (OCS) and applications created using the Cisco Unified CME CTI SDK, and enables click-to-dial from the application.

The CTI CSTA Protocol Suite in Cisco Unified CME 8.8 and later versions enables the dial-via-office functionality from the application.

CSTA Client Application Deployment

Typically, a computer-based application uses CSTA to control its associated PBX phone via a SIP CSTA gateway. The gateway terminates SIP messages and converts ECMA-323 messages to and from the PBX-specific protocol.

In Cisco Unified CME 8.0 and later versions, a computer-based CSTA client application interacts directly with Cisco Unified CME via the CTI interface in Cisco Unified CME to control and monitor IP phones registered in Cisco Unified CME. Cisco Unified CME replaces the CSTA gateway and the PBX in the typical application-to-PBX deployment to terminate SIP messages from the client application and convert CSTA XML into the line-side protocol that controls the phone.

CTI Session

If required, a CSTA client application creates a session by establishing a SIP dialog with the CTI interface in Cisco Unified CME 8.0 and later versions. The logical name of the phone user is described in the SIP “From” header while the PBX phone line is described in the SIP “To” header. The user and line configurations are created in the application.

The SIP INVITE body includes a System Status service request. A SIP “OK” response that includes a System Status response is sent from Cisco Unified CME. The application continues only if it receives the expected response.

After receiving the expected response, the client application begins the capabilities exchange by sending a SIP message requesting a list of supported CSTA services and events from Cisco Unified CME. Cisco Unified CME sends a response with an encapsulated CSTA features response that is a list of supported services and events. For information, see the “Supported Services and Events” section.

The CSTA client application must start a CSTA monitor before it can observe changes to calls and features by CSTA events. To start the Call Monitor Module (CMM) in Cisco Unified CME, the application sends a SIP INFO message with an encapsulated service request. The CTI interface authorizes this request and sends back a SIP 200 OK response with an encapsulated ECMA-323 Monitor Start response. After this, Cisco Unified CME starts generating subsequent events in SIP INFO messages to the application.

During a CTI session, the CSTA client application sets a timer (default: 30 minutes) in the INVITE message and refreshes it via RE-INVITE message. Cisco Unified CME deletes a SIP dialog after the session expires.

Supported Services and Events

Table 50-1 lists CSTA services and events that are supported by the CTI CSTA protocol Suite in Cisco Unified CME 8.0 and later versions. Not all CSTA client applications can support all features. For more information, see the user documentation for your CSTA client application.

How to Configure CTI CSTA Protocol Suite

Table 50-2 contains a list of tasks required to enable a computer-based CSTA client application to control IP phones in Cisco Unified CME, presented in the order in which the tasks are to be completed. This document contains information about performing tasks in the first 2 steps in this table and procedures for completing step 3.

Enabling CTI CSTA in Cisco Unified CME

To configure Cisco Unified CME to enable interoperability between Cisco Unified CME and a computer-based CSTA client application, perform the following steps.

Prerequisites

Cisco Unified CME 8.0 or a later version must be installed and configured on the Cisco router.

(Not required for a MOC client) XML API must be configured to create an AXL username for some CSTA client application access. To determine if an AXL username is required for your application, see your application documentation. For configuration information, see the “Configuring the XML API” section.

Note During the initial setup of the CSTA client application, you need the router IP address configured using theip source-address command in telephony-service configuration mode. For some client applications, you may also need the AXL username and password configured using thexml user command in telephony-service configuration mode.

Examples

Configuring a Number or Device for CTI CSTA Operations

To configure a directory number or an IP phone for CTI CSTA operations, perform the following steps for each number or phone to be monitored and controlled by the CSTA client application.

Prerequisite

Directory number or IP phone to be controlled and monitored by the application is configured in Cisco Unified CME. For configuration information, see the “” section.

Extension Mobility (EM) phone to be controlled and monitored by the application must be configured in Cisco Unified CME, including the required user profiles. For information, see the “” section.

Restrictions

Only SCCP IP phones can be controlled by a CSTA client application. The Cisco VG224 Analog Phone Gateway and analog and SIP phones are supported as usual in Cisco Unified CME but not as IP phones for a CSTA client application.

Overlay DNs are not supported on IP phones for a CSTA client application. The Call Monitor Module in Cisco Unified CME is unable to determine if two inbound calls to the same directory number are on the same phone or on different phones, as in an overlay configuration. Overlays DNs are supported as usual in Cisco Unified CME but not on IP phones to be controlled or monitored by a CSTA client application.

Not all SCCP IP phones support the Prompted Make Call feature in the CTI CSTA protocol suite. The Cisco VG224 Analog Phone Gateway, Cisco ATAs, and SCCP-controlled FXS ports on Cisco routers do not support a prompted make-call request from a CSTA client application. Certain Cisco Unified phone models, including the Cisco Unified 792X and Cisco Unified 793X, may be unable to complete a prompted make-call request from a CSTA client application.

Prompted Make Call is not supported on IP phones associated with a MOC Client. Prompted Make Call is supported as usual in Cisco Unified CME but not on IP phones to be controlled by a MOC client.

Shared lines are not supported on an IP phone associated with a MOC client. Shared lines are supported as usual in Cisco Unified CME but not on IP phones to be controlled by a MOC client.

If the phone to be controlled and monitored by a MOC client is an Extension Mobility (EM) phone, the MOC client must log into the phone using the credential in an EM user profile when no users are logged into the EM phone or after an EM user logs in.

SUMMARY STEPS

1. enable

2. emadmin login name ephone-tag

3. emadmin logout name

4. configure terminal

5. ephone-dn tag

6. cti watch

7. cti notify

8. exit

9. telephony-service

10. em external

11. url services url root

12. end

DETAILED STEPS

Command or Action

Purpose

Step 1

enable

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2

emadmin login name ephone-tag

Router# emadmin login user204 2

(Optional) Enables application to log in to an IP phone that is enabled for Extension Mobility.

name —Credential in EM user profile configured with the user (voice user-profile) command.

ephone-tag —Identifier for IP phone that is enabled for Extension Mobility.

Required for a MOC client if the MOC client will control the number or device to be configured.

Step 3

emadmin logout name

Router# emadmin logout user204

(Optional) Logs the application out of the Extension Mobility phone.

name —Credential in Extension Mobility that the application used to log into an Extension Mobility phone.

Step 4

configure terminal

Router# configure terminal

Enters global configuration mode.

Step 5

ephone-dn tag

Router(config)# ephone-dn 1

Enters ephone-dn configuration mode.

Step 6

cti watch

Router(config-ephone-dn)# cti watch

Allows this directory number to be monitored and controlled by a CSTA client application.

This command can also be configured in ephone-dn-template configuration mode. The value set in ephone-dn configuration mode has priority over the value set in ephone-dn-template mode.

Step 7

cti notify

Router(config-ephone-dn)# cti notify

(Optional) Forces ephone-dn into constant “up” state to allow CTI operations on this directory number.

Required if ephone-dn to be monitored/controlled is not associated with a physical device.

This command can also be configured in ephone-dn-template configuration mode. The value set in ephone-dn configuration mode has priority over the value set in ephone-dn-template mode.

Step 8

exit

Router(config-ephone-dn)# exit

Exits ephone-dn configuration mode.

Step 9

telephony-service

Router(config)# telephony-service

Enters telephony-service configuration mode.

Required only if you perform Step 10 to Step 11 for configuring the Services menu on an IP phone.

RFCs

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Feature Information for CTI CSTA Protocol Suite

Not all commands may be available in your Cisco IOS software release. For release information about a specific command, see the command reference documentation.

Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which Cisco IOS and Catalyst OS software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.

NoteTable 50-3 lists only the Cisco IOS software release that introduced support for a given feature in a given Cisco IOS software release train. Unless noted otherwise, subsequent releases of that Cisco IOS software release train also support that feature.

Table 50-3 Feature Information for CTI CSTA Protocol Suite

Feature Name

Cisco Unified CME Version

Feature Information

CTI CSTA Protocol Suite Enhancement

8.8

Enables the dial-via-office functionality from computer-based CSTA client applications and adds support to CSTA services and events.